1. Field of the Invention
The invention is related to packet network technologies, and in particular, to methods and systems for user based prioritized message processing.
2. Description of the Prior Art
Packet based voice communication networks package and transmit voice communications based on packet protocols. Voice over Internet Protocol (VoIP) networks typify modern packet based voice communication networks. VoIP networks digitize, compress, and convert voice communications to interne protocol (IP) packets. Specialized signaling protocols are then employed to setup and tear down VoIP calls. Specialized signaling is also utilized to locate users across the various VoIP networks. Session Initiation Protocol (SIP) is an example of a well known VoIP signaling protocol.
SIP provides advanced signaling and control to VoIP networks for initiating, managing, and terminating VoIP network sessions, or calls. A typical SIP enabled VoIP network includes user agents, proxy servers, and media gateways. User agents are the end users of a SIP network. User agents can be the origin or destination for a call over a VoIP network. Media gateways interwork communications for calls between VoIP networks and for calls that either originate or terminate outside of a VoIP network. Proxy servers provide registration, redirect, and location services implemented by registrar, redirect, and location server applications running on the proxy servers. In particular, registrar servers manage user agents assigned to their network domains. Redirect servers redirect SIP messages to their appropriate destinations and return location information in response to queries. Location servers share responsibility for knowing the location and status of each gateway.
Telephony Routing over Internet Protocol (TRIP) is a well known protocol established to effectuate messaging between location servers and gateways to keep track of the location and status of the gateways. TRIP does not run directly over IP—it must ride over a telephony protocol like SIP or H.323 because IP does not provide the infrastructure (e.g. SIP proxy server and media gateway) nor the packet structure to provide what TRIP needs to do its very specific job (dynamic building of proxy server routing tables). In a SIP only network, location servers are not utilized; rather, the proxy server uses standard Domain Name Service (DNS) methods to determine where to forward call requests. In a TRIP enabled SIP network, the location server builds a dynamic routing table based on TRIP update messages transmitted from various media gateways and location servers. The location server then accesses the resulting TRIP routing table to determine where to forward and redirect call requests.
TRIP enabled location servers are often referred to as TRIP speakers. A scaled down version of TRIP called TRIP-lite can be implemented on gateways. TRIP-lite transmits messaging from a gateway to at least one location server advertising the available routes and prefixes accessible through that gateway. For example, a first TRIP-lite enabled gateway might advertise to a location server that it services the 913 area code of the public switched telephone network (PSTN), while a second TRIP-lite enabled gateway advertises to the location server that it services the 816 area code of the PSTN. Thus, when a call request indicating a PSTN area code of 913 arrives into the location server, the location server knows to route that call to the first TRIP-lite enabled gateway. Other attributes advertised by TRIP-lite enabled gateways include destination prefixes, capacity to each prefix destination, and utilization levels of each trunk group terminating at the gateway. TRIP-lite allows location servers to have real-time knowledge of available gateway resources.
One problem with current VoIP network configurations is the inability of the networks to deliver consistently high levels of quality of service (QoS) on a per user basis. For example, when a SIP enabled location server receives multiple update messages from several TRIP-lite enabled gateways, the volume of messages could push the location server into a period of congestion. Currently, the location server has no way to prioritize the messages to ensure a basic QoS level across the network. Additionally, the location server has no way by which to ensure a QoS level for specific VoIP users of the network. Thus, the location server treats each update message as if each update message is as important as any other. However, the content of some of the update messages are typically more important than the content of others. Furthermore, some users accessing the network may be more important than other users accessing the network. Therefore, it would be useful and desirable to provide varying levels of QoS for various users when processing update messages to build network routing tables.